Q: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Great Barrier Reef: Making clouds brighter could help to curb coral bleaching, scientists say 
  
 Posted 
  
 Marine scientists have upped the ante in their fight to save the Great Barrier Reef from the devastating effects of coral bleaching. 
  
 Key points: Cloud brightening involves making larger and more reflective clouds over the ocean 
  
 The more reflective clouds help to cool the water underneath 
  
 Researcher Daniel Harrison says it should be a temporary, stop-gap measure only 
  
 A team of Australian researchers at the Sydney Institute of Marine Science is working on plans to alter the clouds above the reef in a bid to save the delicate coral communities below. 
  
 Marine cloud brightening is the process of making larger and more reflective clouds over the ocean to cool the water underneath. 
  
 It may seem far-fetched, but Daniel Harrison, a postdoctoral research associate with the Ocean Technology Group at the University of Sydney, believes it could work. 
  
 "All of our preliminary calculations so far suggest that it is plausible," Dr Harrison said. 
  
 "You can think about this in very layman's terms. 
  
 "If you're in a hot sunny day and a cloud comes across overhead, you can feel right away there's quite a lot less heat coming through." 
  
 The Great Barrier Reef is one of the natural wonders of the world, but with two-thirds of the reef already damaged, marine scientists fear the entire system has reached a critical tipping point. 
  
 As the bleaching continues, they are getting increasingly desperate. 
  
 Dr Harrison and his team considered several other approaches, including pumping cool water onto the reef in a bid to cool it during times of extreme heat. 
  
 But they believe the cloud-altering technology is the most feasible, sensible, and environmentally benign option for preserving the reef. 
  
 "If we can make just a little bit less heat over the reef for a few months during say an El Nino year, when it's at most risk of getting bleached, we should be able to cool the water a degree or two, which is enough to prevent most of the damage," he said. 
  
 'Maybe we can cool the entire planet by brightening the clouds' 
  
 The idea that scientists can counteract the damages of global warming by re-engineering the climate is not new. 
  
 In the past, researchers have used salt particles to brighten low-level clouds, which promote droplet formation and lead to bigger and denser clouds. 
  
 But it is believed to be the first time a geo-engineering solution such as cloud brightening has been considered for the Great Barrier Reef. 
  
 "Cloud brightening was conceived as a potential fallback," Dr Harrison said. 
  
 "If we can't get emissions under control, maybe we can cool the entire planet by brightening the clouds. 
  
 "But nobody has thought about applying it to a small local area of a coral reef to prevent bleaching before." 
  
 'It might be the only way to save the reef' 
  
 Aerial surveys conducted earlier this year by the ARC Centre of Excellence for Coral Reef Studies show the bleaching of coral in the Great Barrier Reef is much worse than first thought. 
  
 The data indicates the reef is struggling through a second consecutive year of serious and widespread bleaching, with two-thirds already devastated. 
  
 The northern sections of the reef were badly damaged by excessively hot conditions in 2016 and the new surveys reveal that the bleaching has now spread to the middle section of the reef. 
  
 But are we ready to deploy a tool that could significantly change the climate? 
  
 Dr Harrison has warned any move to brighten clouds above the reef is a temporary, stop-gap measure only, while the real focus needs to be on reducing carbon emissions. 
  
 "If we don't reduce emissions then I don't think the reef really has much chance of surviving in its current configuration at all," Dr Harrison said. 
  
 "At the moment, we've only experienced a little bit less than 1 degree [Celsius] of average global temperature rise. 
  
 "So if you can imagine how badly this is affecting the reef now, at 1.5 or 2C the reef has no chance. 
  
 "Which is why — although we wouldn't want to have to do these geo-engineering ideas and deliberately make clouds over the reef if we didn't have to — we think we need to look into this because it might be the only way to save the reef." 
  
 Topics: climate-change, environment, great-barrier-reef, oceans-and-reefs, science-and-technology, weather, port-douglas-4871, cairns-4870, townsville-4810, qld, australia, sydney-2000, nsw ||||| A group of Australian marine scientists believe that altering clouds might offer one of the best hopes for saving the Great Barrier Reef. 
  
 For the last six months, researchers at the Sydney Institute of Marine Science and the University of Sydney School of Geosciences have been meeting regularly to explore the possibility of making low-lying clouds off the northeastern coast of Australia more reflective in order to cool the waters surrounding the world’s biggest coral reef system. 
  
 During the last two years, the Great Barrier Reef has been devastated by wide-scale bleaching, which occurs as warm ocean waters cause corals to discharge the algae that live in symbiosis with them. Last year, as El Niño events cranked up ocean temperatures, at least 20 percent of the reef died and more than 90 percent of it was damaged. 
  
 The Australian researchers took a hard look at a number of potential ways to preserve the reefs. But at this point, making clouds more reflective looks like the most feasible way to protect an ecosystem that stretches across more than 130,000 square miles, says Daniel Harrison, a postdoctoral research associate with the Ocean Technology Group at the University of Sydney. “Cloud brightening is the only thing we’ve identified that’s scalable, sensible, and relatively environmentally benign,” he says. 
  
 Bleached corals on the Great Barrier Reef. Ed Roberts/Tethys Images | ARC Centre of Excellence Coral Reef Studies 
  
 They’re one of several research groups that have started to explore whether cloud brightening, generally discussed as a potential tool to alter the climate as a whole, could be applied in more targeted ways. All the scientists involved stress that the research is in its infancy. No one has tested a system for cloud brightening at all, much less in geographically focused applications. 
  
 British scientist John Latham first proposed the idea as a potential way of controlling global warming in Nature nearly 30 years ago. The theory is that fleets of ships could spray tiny salt particles, generated from sea water, toward the low-lying marine clouds that hug the coasts of several continents. That would provide the nuclei needed to induce additional droplet formation, expanding the total surface area of the clouds. The resulting dense, white clouds should reflect more heat back into space. A 2012 study led by Latham at the University of Manchester found that the approach could offset the heating that would result if carbon dioxide doubled in the atmosphere. 
  
 The Marine Cloud Brightening Project, a collaboration between a group of Silicon Valley researchers and University of Washington climate scientists, has done the most advanced work on the idea to date. The team in Sunnyvale, California, has spent the last seven years developing a nozzle that they believe can spray salt particles of just the right size and quantity to alter the clouds. They’re attempting to raise several million dollars to build full-scale sprayers, in hopes of eventually conducting small-scale field trials at some flat point along the Pacific coastline—ideally a place with onshore winds, low-lying clouds, and open-minded neighbors. 
  
 The Marine Cloud Brightening Project's nozzle sprays a fine mist of tiny salt particles. JAMES TEMPLE 
  
 They’re among a handful of researchers looking to conduct limited outdoor experiments to explore the feasibility and risks of such approaches (see “The Growing Case for Geoengineering”). But while the prospect of using geoengineering to ease global warming on a large scale poses intractable governance issues, using the technology to address a more localized problem could be more feasible, at least politically. 
  
 Coral reefs are crucial parts of the ocean ecosystem, providing hunting grounds and homes for thousands of species. They also generate nearly $200 billion in economic value annually, through tourism, fisheries, and other activity, according to one study. Reefs, however, have been hard hit worldwide by ocean acidification, pollution, overfishing, and other environmental stresses. The Great Barrier Reef has shrunk dramatically during the last three decades. 
  
 That makes it increasingly urgent to seriously explore ways of preserving the reefs, even “fairly out-there, grand schemes,” Harrison says. Next month, he plans to start computer climate modeling to explore whether cloud brightening could make a big enough temperature difference to help. The group plans to collaborate on the research with the Marine Cloud Brightening Project team. 
  
 Coral reefs aren’t the only ecosystem that some scientists believe might need help from geoengineering. Researchers at the University of California, the Carnegie Institution, Stanford University, and Oregon State University have begun a larger project exploring, among other things, how climate change is affecting or will affect the last remaining stands of coast redwoods. 
  
 They're the world's tallest trees, and rely on coastal fog for around half of their moisture. But Northern California fog levels have dropped more than 30 percent since the early 20th century, a decline linked to urbanization and climate change. The impact has been limited to date, but fear is growing that these old-growth stands could be wiped out if the trends accelerate. 
  
 Elliott Campbell, an associate professor of environmental engineering at UC Merced, says the group has held early talks with the Marine Cloud Brightening Project about whether the technique could generate more low-lying clouds to help feed moisture to the redwoods. “If we could artificially produce fog on summer mornings, and that could help us buy the redwoods more time as we shift to a less carbon-intensive economy, that’s potentially a good thing,” Campbell says. 
  
 Aerial view of a bleached portion of the Great Barrier Reef. ARC Centre of Excellence Coral Reef Studies 
  
 Ken Caldeira, a prominent climate scientist at the Carnegie Institution who has modeled the potential of cloud brightening, says the idea of localized geoengineering is worth exploring. But he’s not convinced that cloud brightening could produce a substantial climate effect at such a limited level. Below a certain geographic footprint, probably around 10,000 square miles, it might be difficult to produce a big enough change in cloud density to add up to much of a difference, he says. He’s specifically skeptical that it would work at the Great Barrier Reef. 
  
 “I just don’t think there are enough clouds of the right type there that would be susceptible to marine cloud brightening,” he says. 
  
 The University of Sydney’s Harrison is aware of the concerns Caldeira raises and intends to look at these issues closely in his feasibility research. But at a first pass, he believes there could be sufficient marine clouds to help preserve the Great Barrier Reef. 
  
 In any case, he hopes so, because nothing else looks particularly promising. |||||
A:
You'd think the search for a solution to bleaching coral in the Great Barrier Reef would have scientists looking down into the ocean, rather than up at the sky. But clouds could be key to combating warming ocean temperatures blamed for the bleaching, say Australian researchers. They believe that "brightening" low-level clouds over the 1,400-mile stretch of coral reef—boosting their ability to reflect the sun's rays back into space—could "cool the water a degree or two, which is enough to prevent most of the damage," Daniel Harrison of the University of Sydney tells Australia's ABC News. It could work like this: Salt particles from the ocean would be directed at the clouds, triggering more water droplets to form and thus creating larger, denser clouds. Cloud brightening was first proposed as a way to cool the planet some 30 years ago and one study claims it could offset the ensuing global warming if carbon dioxide doubled in the atmosphere, reports MIT Tech Review. But though research is ongoing—one company has spent seven years developing a nozzle to shoot the salt spray—trials have been few and far between. Australian researchers—who stress the need to reduce carbon emissions—now hope to determine, through computer modeling, if cloud brightening on a small scale would make a real difference. And there's a lot riding on the research. "Cloud brightening is the only thing we've identified that's scalable, sensible, and relatively environmentally benign," Harrison says. (A total wipeout of coral is possible.)